Structure of the Nerve Root

The principal terra incognita in the histology of the cerebrospinal nerve root has concerned its central glial segment and the nature of its junction with the peripheral segment. The inadequacy of staining technic has been largely the cause of the retardation in the study of these problems. Recent improvements in the metallic impregnation methods of the Spanish school, enabling a more complete portrayal of neuroglia, Schwann cells and reticulin, afford an opportunity to supply this deficiency. My purpose in this investigation has therefore been a study of the central glial segment of the nerve root and the nature of its junction with the peripheral nerve segment. HISTORICAL REVIEW That a nerve root contains a central glial segment and a peripheral nonglial segment was recognized soon after Virchow discovered neuroglia by Thomsen 1 and many others. Staderini, 2 as well as Weigert, 3 subsequently showed that the neuroglia is more dense